Diff: dftReal.hpp

Revision:

4:8248d5b5cdc9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dftReal.hpp	Sat Dec 12 03:21:58 2020 +0000
@@ -0,0 +1,29 @@
+//--------------------------------------------------------------
+//	離散的フーリエ変換 (DFT)
+//
+//  2020/12/12, Copyright (c) 2020 MIKAMI, Naoki
+//--------------------------------------------------------------
+
+#include "mbed.h"
+#include <complex>  // complex で使用
+
+#ifndef DFT_REAL_HPP
+#define DFT_REAL_HPP
+
+typedef complex<float> Complex;     // "Complex" の定義
+
+void DftReal(const float x[], Complex y[], int nFft);
+
+//  DFT の計算
+void DftReal(const float x[], Complex y[], int nFft)
+{
+    Complex j2PiN = Complex(0, -6.28318531f/nFft);
+
+    for (int k=0; k<nFft; k++)
+    {
+        y[k] = 0.0;
+        for (int n=0; n<nFft; n++)
+            y[k] = y[k] + x[n]*exp(j2PiN*(float)(n*k));
+    }
+}
+#endif	// DFT_REAL_HPP
\ No newline at end of file